We have a Thermolaire LP freestanding heater that we use to heat a vacation home. I don't know the model number, but it delivers around 60000 BTU. The past couple of years, the burner has had trouble catching. Gas builds up and it will eventually ignite, but sometimes with a boom. We got a wire brush and cleaned all the burner holes, this helped a little, but eventually the problem returned. Sometimes the pilot light may go out as well, if there is much air movement such as a ceiling fan running or draft. I know little about these types of heaters, and am unsure of who to call or how to fix it. The brand has been defunct for 25+ years. Any recommendations?

Your best bet is to update the unit.

If you have an air compressor blow the dust out of it. Vacuum it that might help. I would not trade mine in for a new one cause mine heats my 1056 sq ft home very well. Its old and I have to manually light the pilot light but other than that the heat from it is great.

On older units like thus, you can usually adjust the pilot. Turn the fan so it blows up and you may eliminate the problem.Lp gas is heavier and can be more difficult to ignite then NG. My space heater has a similar issue, particularly when cold starting.

I discovered there is a way to adjust the air-gas mixture. I might try that. Thanks for the suggestions.